Table 2.

Summary of GEE Model Predicting Hangover Severity as a Function of Age and Drinking

			95% CI
Predictor	β	SE	LL	UL	p
Age	−0.122	0.049	−0.217	−0.026	.012
Sex	−0.087	0.053	−0.191	0.018	.105
Between-person drinking volume	0.262	0.062	0.141	0.383	< .001
Within-person prior day drinking volume	0.250	0.034	0.182	0.317	< .001
Age × Sex	0.014	0.049	−0.081	0.109	.770
Age × Within-person prior day drinking volume	−0.088	0.031	−0.149	0.027	.005
Sex × Within-person prior day drinking volume	0.003	0.034	−0.064	0.071	.923

Note: Continuous measures are standardized. Sex was coded −1 for females and 1 for males. The reported coefficients represent standardized effects (effect size d). GEE = generalized estimating equation; SE = standard error; CI = confidence interval; LL = lower limit; UL = upper limit; Between-person drinking volume = grand-mean centered average number of standard alcoholic drinks consumed on drinking days during the monitoring period and reflects the between-person effect; Within-person prior day drinking volume = person-centered number of standard alcoholic drinks consumed the day before each hangover assessment and reflects the within-person effect; The pattern of significant results remained unchanged when the data source (i.e., sample) and person-level covariates (i.e., alcohol dependence, baseline drinking levels, and weight) were included in the model. Thus, we report the results of the final model without these additional covariates to preserve statistical power. The three-way interactive effect of age, sex, and within-person prior day drinking volume was not significant, and exclusion of all main and interactive effects of sex also did not alter our pattern of significant results.